1. Technical Field
This invention relates in general to data cartridges and in particular to a data cartridge of magnetically recorded tape with a single reel that is capable of recording on both sides of the tape.
2. Background Art
Data cartridges containing one or more spools of magnetic media tape are well known in the prior art. The data cartridges are typically mounted in a tape drive unit and the spools are rotated by a spindle motor at selected speeds by the tape drive unit. In some data cartridges, the magnetic tape is simply conveyed internally within the cartridge from one spool to another. In other data cartridges, the magnetic tape is spooled out of the cartridge and onto a take-up reel located on the drive unit. In either configuration, one side of the tape is usually read or written to by a magnetic head located adjacent to the cartridge.
In the prior art, attempts have been made to improve the efficiency of data cartridges. For example, in U.S. Pat. No. 4,000,519, a cassette of two-sided magnetic tape has two reels which circulate the tape within the cartridge. Both sides of the tape are accessed through a pair of oppositely-facing windows in the cassette. A similar design is disclosed in Japanese patent JP53-144710. In that patent, the two-sided magnetic tape of a cassette is drawn out of the cassette through two opposite openings so that both sides of the tape can be read and/or written to by the tape drive.
A third example is described in U.S. Pat. No. 3,974,975, where a cartridge tape has a single reel of two-sided magnetic tape, and two oppositely-facing tape access windows. Apparently, the reel winds and unwinds the tape at its outer tape diameter and inner hub diameter simultaneously to make use of the single reel. In order to access both sides of the tape, the tape is twisted 180 degrees at two different locations inside the cartridge. Although these designs are workable, an improved, more reliable data tape cartridge is desirable.